He added that his stance would depend on the wording and he was “not sure” if Cabinet Ministers could express personal opinions on the issue.

“What’s going to happen anyway is that the constitutional convention is going to deliberate on the matter and make a recommendation to Government,” he told the Today with Pat Kenny show on RTÉ Radio One.

Asked about his own stance, he said: “I suppose, depending on the proposition, if there was a referendum on it, I would probably vote Yes.”

He cited the example of a gay couple he knew who had been legally married in Belgium but their union was not recognised in Ireland.

“I do think there is a difference when it comes to raising children. I do think that, by and large, children are best raised in a household with a mother and father but that isn’t always possible, for different reasons.

“But I don’t see why a same-sex couple shouldn’t be allowed to be married if they wish to,” Mr Varadkar added.

“I don’t think it would damage society, I don’t necessarily think it would damage the family.”

Labour Senator Ivana Bacik, a strong supporter of marriage equality for gay couples said later: “I welcome his comment. I accept that it is a personal view.

“He is stating probably a very commonly held position: it is quite a representative view.”

Fianna Fáil leader Micheál Martin is to press the Taoiseach on his position in the light of his refusal to clarify his stance in an encounter with journalists outside the National Library of Ireland last week.

A spokesman said Mr Martin would be raising the issue in the Dáil this week and “seeking to get an answer to the question of what is the Taoiseach’s view of marriage equality”.

On Fianna Fáil’s own stance, the spokesman said: “The ardfheis expressed support for marriage equality and Micheál has given his personal support to it.”

A Sinn Féin spokesman said the party “supports gay marriage and adoption rights for gay couples”.